MDE-3664B TRIND® Start-up, Service, and Parts Manual · June 2013
Page 4-17
TRIND Overhead Antennas
Major Hardware Components
Single-loop Overhead Antenna Assembly (T20632)
The Single-loop Overhead Antenna Assemblies (T20632-GX) are made up from a single turn
(loop) antenna; a high-efficiency tuning board, and a UHF receive antenna. These parts are all
mounted in a molded polycarbonate set of boxes and then mounted with brackets on top of the
dispenser. These parts are discussed in further in the following sections.
Note: There are eight different “G” levels of this antenna assembly, due to the different widths
and heights of the dispensers.
T20632 “G” Level
Dispenser Antenna is used
G1/G5
Advantage Wide Frame and MPD-3
G2/G6
Advantage Narrow Frame
G3/G7
Encore
G4/G8
Advantage Wide Frame with Exxon
®
Light Box
SMA connections should be treated with care and not overtightened. The
maximum torque rating on these connectors is usually measured in inch pounds
Too severe a turn or bend in the cable may damage the center conductor or
compromise the shield/drain portion of the cable.
This can result in an observance of intermittent reads or other problems. The poor
performance will in turn generate a premature field service call. Replacing this
cable is labor intensive after the system is installed the first time.
Turns or bends in co-axial cable must be gradual loops, no sharper than a 1-inch
radius (2-inch diameter).
CAUTION
CAUTION
It is critical that the proper tool is used when tuning the overhead antennas on
TRIND systems. Only the Q13631-02 [part of Authorized Service Contractor (ASC)
Tool Kit K94577-01] plastic tuning tool (or similar plastic 0.10-inch hex tool) should
be used for tuning overhead antennas.
Using a metal screwdriver or Allen
®
wrench has two negative effects. First, a
proper tuning is impossible as the metal of the tool used changes the properties of
the variable inductor used for tuning. Second, the ferrite slug used in the variable
inductor is extremely brittle and is broken or stripped easily by metal tools,
preventing the proper tuning of the antenna.
If the antenna is not properly tuned the read range can be significantly reduced.